I. Field of the Invention
The present invention relates to medical diagnostic techniques including computed tomagraphy scanning of a patient, and more particularly to a device for guiding a biopsy needle to an exact location based on information obtained by computed tomagraphy scanning.
II. Prior art
A number of devices currently exist for making physical measurements of a patient's body or parts thereof. U.S. Pat. No. 4,135,498 issued to McGee includes a non-opaque viewing screen with a vertical scale, a measuring bar with slides along the vertical scale, and an angle measuring arm and angular scale. The patient stands behind the screen, and X-rays are aligned on the screen relative to the patient and illuminated. Measurements of the patient in relation to the X-rays may thus be made.
U.S. Pat. No. 4,440,168 to Warren is for a surgical device for marking angles and positions on bones or other body tissue with respect to a reference point, in preparation for surgery.
U.S. Pat. No. 4,630,375 to Spolyar is for a template-like gauge having a reference point and linear and angular scales relative to the reference point. The gauge is used in connection with a standardized lateral cephalogram of a patient to precisely determine spatial coordinates for focusing an X-ray source in obtaining a radiograph of the patient's temporo-mandibular joint.
U.S. Pat. No. 4,279,259 to Lee discloses a mammometer for making various breast-related measurements, including location, shape, size, necessary for various kinds of breast surgeries.
It has long been possible to focus sources of radiation, including X-rays and laser beams, at an exact location within the human body. The development of computed tomagraphy scanners has made possible the determination of spatial coordinates of a diseased or problem area within the body. However there are no known devices for guiding a biopsy needle to a precise location within the body.
Accordingly it is an object of this invention to provide a biopsy needle guide for use in connection with a computed tomagraphy scanner, which can measure and control the angle and depth of penetration of a biopsy needle in a given cross-sectional plane of a patient's body, so that the physician may insert the biopsy needle to the precise location determined from the tomagrams.